The aim of the present study was to investigate the colonic mucosal and cytobrush sample mRNA expression of IL-1β, IL-2, IL-12p40, IL-23p19, TNF-α and C‐C motif chemokine ligand (CCL28), using real-time RT-PCR, as well as the correlations of mRNA expression in the colonic mucosa with the cytobrush samples of dogs with large intestinal IBD. This evidence concerns the gene IL2 and inflammatory bowel disease.